Water softening apparatus



June 14, 1938. J NASH 2,120,429

WATER SOFTENING APPARATUS Filed Feb. 27, 1936 INVENTOR A TORNEYS Patented June 1 4, 193$ UNITED STATES PATENT OFFICE WATER. SOFTENING APPARATUS John H. Nash, Dayton, Ohio Application February 27, 1936, Serial No. 65,986

1 Claim. (Cl. 210 -24) This invention relates to improvements in base exchange water softening apparatus, it more particularly relating to the apparatus for producing the brine solution for regenerating the exchange material.

One of the objects of the present invention is to provide a comparatively large saturator in which may be made and stored a comparatively large quantity of brine, thereby fitting the saturator for service with a battery of softeners, or providing sufficient brine to regenerate a single softener several times.

A further object of the invention, in order to eliminate salt encrustation and corrosion of the metals of which the saturator is made at the brine level due to contact with air, is to provide in the saturator that two compartments are formed in effect, a brine compartment and a fresh water compartment, whereby, as the brine is heavier due to the diiference in specific gravity, the fresh water remains above the brine.

I avail myself of the fact that the fresh water will remain above the brine by providing that the fresh water compartment is of such size and capacity that even the larger quantities of salt that can be used in this saturator are completely submerged, leaving a stratum of fresh water above the uppermost portions of the salt. This extreme upper stratum of fresh water can not do otherwise than remain fresh, as its upper portion can not sink to the salt level. Therefore, as any corrosion of metals by brine in contact with air can not take place in this saturator since air is not in contact with the brine, the metals of the saturator are protected.

In this saturator, also, there is no need of supplying measured quantities of salt per quantities of fresh water. Fresh water, of course, is added from time to time to make up for any evaporation, or for :withdrawal of brine as will be described, but as large a quantity of salt may be placed in the salt carrying receptacles at any time as can be accommodated. The formation of brine goes on automatically and stops and starts according to whetherthe stored brine solution is at its maximum saturation or not. For this reason, salt may be added at the convenience of the operator even though the solution is then at its greatest quantity and greatest degree of saturation.

In view of the larger quantities of salt that are to be handled, it is another object to provide a low-down or floor-level saturator to eliminate unnecessary lifting of the salt to an overhead position, and this feature also makes it possible to install the apparatus in places where the head room is not sufficient to accommodate a gravity flow device such as is shown in my Patent No. 1,940,965, dated December 26th, 1933. f

To cause the flow of brine through the exchange 5 materials, I prefer to employ an electrically driven pump, and to prevent corrosion of the pump and its fittings I submerge the pump in a so-called pump sump connected to the saturator flows in the pump sump and establishes a brine compartment in the sump. As the pump discharges this brine, more brine flows from the saturator to the sump. This obviously lowers the level in the saturator which is made up by the admission of fresh water to the proper height, and in the present instance, fresh water is also added at the same time to the upper portion of the sump and thereby maintains an upper stratum of fresh water in the sump above the brine therein and thereby forms a fresh water compartment in the sump, this fresh water protecting the pump from corrosion. This feature makes it possible to provide an ordinary pump for the installation, that is, it is not necessary to employ the more expensive corrosion resisting alloys in the manufacture of the pump.

Another object and advantage is that by proper proportionlng and placement of the pump sump in relation to the saturator, that an overflow opening in the pump sump takes care not only of the liquid level in the sump but also of that in the saturator. This is advantageous in that the operator need only be instructed to re-flll with fresh water so that the level in the saturator reaches a certain definite, marked height therein; no allowance need be estimated for the salt that will later form brine to cause a refilling to a point below the proper level. This feature is further explained in the specifications.

In the accompanying drawing:

The figure is a conventional view showing in elevation partly broken away of the improved brine producing apparatus in connection with typical softeners.

Referring to the drawing, at I is shown a typical base exchange softener and at v I a portion of another, the two representing a part of a battery of similar softeners. In each softener, the exchange granules are shown at 2, while in l 50 the gravel diifuser bed is indicated at 3. The nozzle through which the fresh water enters during ordinary service is shown in broken lines at 5 in the softener l,it being understood that each softener is similarly equipped. The fresh or hard 5 and a valve I. An identical system is also shown in connection with the second softener I. Above the broken line 0' in each softener is the'freeboard space, and in the upper portion of the softener I is shown at I. the mineral screen which prevents the exchange granules from passing through the filler device I I into the house pipe l2.

The saturator is shown at the right and is indicated in general as 8. This is a comparatively large tank or tub it open at the top, set on the floor on legs I 3' and having a cover II". There is a plurality of angle brackets ll attached to the inner surface of the vertical walls of the tank at some distance down from the open end, on which brackets is supported the salt basket I! formed of wire mesh. At It is shown the salt, preferably in cloth bags, resting in the salt basket. As can be seen, the salt is entirely covered by water, the water being let into the tank ll until the proper level at I! is reached, this mark in the present case being formed by rolling an annular bead It in the side wall of the tank. A gauge glass I1 is fitted to the tank so as to give an indication of the height of the contained liquid.

As previously stated, the saturator is placed on the floor to avoid lifting of the heavier quantitles of salt possible to use in this larger saturator, and to cause the brine to flow through the exchange materials a small electrically driven pump, shown at is, is employed, 20 being the motor by which the pump is driven by a shaft not shown. For reasons which will appear, the pump is housed in a so-called pump sump 2|, which is a tank smaller in diameter and of slightly greater length than the saturator tank I I, and is also placed somewhat higher above the floor than the saturator. The sump 2| is connected to the saturator I: by the single pipe connection 22, whereby liquid from the saturator may flow into the sump 2!.

The pump discharges through a pipe 23 having a check valve 24 and valve 25, to the branch pipe 7 of the softener i, and at 26 is shown a pipe leading around the softener I to the corresponding branch pipe 1' for the softener I. It will be obvious that if there are other softeners in the battery, these softeners will be similarly connected to the pump.

A fresh water pipe 21 conducts water from the service pipe 6 under control of the valve 28 to both the saturator l3 and the sump 2| through the connections 22'.

The operation is as follows: The water valve 28 is opened and the water flows into the saturator and sump until the proper water mark I8 is reached, and salt in any quantity or form is placed in the salt basket. So long as the water is fresh, the level in both saturator and sump will be equal, as the two devices by reason of the connection pipe 22 are in effect a U-tube, but as soon as the salt begins to dissolve into the fresh water, brine begins to form, which by reason of its greater specific gravity, settles to the bottom of both the saturator and the sump.

Assuming that a sufficient quantity of salt has been placed in the basket, the formation of brine goes on until the dense brine builds up to the proximity of the salt, where no more salt will be dissolved due to lack of opportunity of circulation; that is, to form brine, the fresher water must be given an opportunity to flow through the salt, which it can not now do, as, the heavier brine prevents any downward flow or circulation of the fresher water. In this way, the strong brine liquid is prevented from attaching the metals of the tank where such corrosion is induced by the oxygen of the air, as there is interposed between the air and the brine, the stratum of fresh water.

There is thus formed in the saturator, a brine compartment extending from the bottom upwardly to the proximity of the salt and indicated by the heavier horizontal lines by which liquids are indicated, and a fresh water compartment above the brine to the water mark I 8, indicated by the lighter horizontal liquid lines. There are also brine and fresh water compartments in the sump 2|. the brine does rise to as great a height in the sump as in the saturator, this height being approximately indicated by the heavy liquid shade lines. This portion is the brine compartment and the lighter liquid shade lines thereabove indicate the fresh water compartment of the sump. It will be noticed that the high level line in the sump, at the upper portion of the fresh water, is higher in the sump than the high level of. the fresh water in the saturator. This is because of the greater. depth of the brine in the saturator, the effective depth extending from the proximity of the salt to the pipe connection 22. As stated, the brine does not build up to so great a height in the sump as in the saturator, therefore, a greater depth of fresh water supported above the brine in the fresh water compartment of the sump is necessary to balance a column of brine and fresh water and brine in the saturator.

It was previously mentioned that an overflow outlet is placed in the side wall of the sump, which overflow governs the level of liquid in both sump and saturator, and that when the saturator is filled to the water mark 18, the later addition of salt would not cause the level to rise in the saturator. By placing the overflow indicated at 29 in the sump at or slightly below the-fresh water level therein when the satura-.

valve 8 in connection with the softener I, is-

closed, also the valve 30 controlling the flow of softened water to the house pipe l2, the valve 3| in a pipe 32 leading to the sewer is opened, the valve 25 in the pump discharge line 23 is opened, and the pump started.

The pump l9 draws brine from the brine compartment in the sump and from the similar compartment in the saturator. The pipe connection 22 connecting the sump to the saturator is comparatively large, so that a free flow of brine from the brine compartment to the suction side of the pump is obtained, and obviates the drawing down and mixingof the fresh water of the fresh water compartment of the sump with the brine. The discharge of the pump is through the pipe 23, check valve 24 and valve 25 to the branch pipe I, through the nozzle 5 and upwardly Due to the single connecting pipe 22,

through the gravel bed 3, exchange granules 2,

through that portion of the house pipe l2 connected to the filler device II to the opened valve 3| and thence to the sewer.

The pump is is allowed to operate until the required amount of saturated salt solution is pumped into either or all of the softener units, if all require regeneration, until the units have been given the proper amount of saturated solution. The pump is then shut oif and the valves 25 and 25' are closed and the valves 8 and 8' are opened wide and the residue salt solution, calcium and magnesium chloride, is washed to the sewer through valve 31 in the pipe 32 for the unit I, and through the corresponding valve and pipe (not shown) for the unit I if that unit is being simultaneously regenerated; this pipe 32 for the unit I and the corresponding pipe for the unit I being the waste pipes to the sewer. When testing and soft water shows at the end of the pipe 32 for the unit I or the corresponding pipe for unit I, the valve 3| for the unit I and the corresponding valve for the unit I are closed and the softener or softeners can then be returned to service by opening the valve or valves in the soft water lines.

The saturator is then re-filled to the water mark I8 with water (fresh) from the service pipe 6 through the pipe 21. Also incidentally the sump receives fresh water, as the pipe 21 is branched to provide the pipe 21' leading to the sump. It should be noted that the pipe 21 leading to the saturator and the pipe 21' leading to the sump are each equipped at their lower ends with suitable nozzles 32 so designed as to allow the fresh water to issue with a minimum directly downward flow which would otherwise disturb the protective upper stratum of fresh water in the saturator and sump. It is also preferable to provide that the nozzles do not extend to the water level in order that leakage of the valve 28 will disclose itself. As stated, the operator needs to watch only the water mark l8 to know when the proper amount of fresh water has been added.

Having thus described my invention, I claim:

In a water softening apparatus, a mineral tank, a brine tank supported independently of said mineral tank, a salt support in said brine tank located intermediate the top and bottom thereof so as to provide in effect a compartment for the brine below said support and a compartment for fresh water above said support, a pump, a housing for said pump having its lower end in communication with the lower end of said brine tank, said pump being located in the brine in said housing, a communication between said pump and said mineral tank, and means for supplying fresh water to the upper ends of the pump housing and the brine tank.

JOHN H. NASH. 

